High Efficiency Chiller Refrigerant Charge vs. Capacity

It seems to me that an unintended consequence of selecting a high efficiency water cooled centrifugal chiller ( both R-123 and R-134a) is the greater difficulty keeping impact per ton below 100 needed to achieve EAc4. I believe the reason is as the chiller manufacturers push their compressor/condenser/evaporator combinations to achieve high energy efficiency(low kw/ton); they find the need to add more and more heat exchanger surface. Along with heat increased heat exchanger surface comes more refrigerant. I have seen this play out with chillers from two major MFR. using two different refrigerants. Has anyone else had any experience with this phenomenon??